High-voltage circuit-interrupter having a closing resistance and improved shunting-resistance contacts therefor

ABSTRACT

An improved high-voltage circuit-interrupter is provided having series main contacts and resistance contacts with a closing resistance shunting the resistance contacts, so that the closing resistance is inserted into the circuit during the closing operation of the high-voltage circuit-interrupter, but is out of the circuit during the opening operation. An improved mechanism is provided for utilizing the inertia of the movable resistance contact-frame and a relatively light biasing means, such as a light compression spring, for example, to ensure that the resistance contacts remain closed, during the beginning of the opening operation of the breaker, so that the closing resistance is shorted out, and the task of extinguishing the established arc or arcs is imposed only upon the main contacts and not at the resistance contacts. During the closing operation, the construction is such that the main driving frame, carrying the movable main contact or contacts, carries therealong also the movable resistance contactframe, with the contact overlap distance being such that the main contacts are closed prior to the closing of the serially-related resistance contacts, thereby inserting the closing resistance into the circuit momentarily during the closing operation of the high-voltage circuit-interrupter.

United States Patent 1 Rostron et al.

1 1 Jan. 28, 1975 1 HIGH-VOLTAGE CIRCUIT-INTERRUPTER HAVING A CLOSING RESISTANCE AND IMPROVED SHUNTlNG-RESISTANCE CONTACTS THEREFOR [75] Inventors: Joseph R. Rostron, Monrocville;

Sylvester .1. Dropik, Jeannette. both of Pa.

[73] Assignee: Westinghouse Electric Corporation,

' Pittsburgh, Pa.

[22] Filed: Dec. 4, 1973 211 Appl. No.: 421,574

Primary Examiner-Robert S. Macon Attorney, Agent, or FirmW. R. Crout [57] ABSTRACT An improved high-voltage circuit-interrupter is pro vided having series main contacts and resistance contacts with a closing resistance shunting the resistance contacts, so that the closing resistance is inserted into the circuit during the closing operation of the high-voltage circuit-interrupter, but is out of the circuit during the opening operation. An improved mechanism is provided for utilizing the inertia of the movable resistance contact-frame and a relatively light biasing means, such as a light compression spring. for example, to ensure that the resistance contacts remain closed, during the beginning of the opening operation of the breaker, so that the closing resistance is shorted out, and the task of extinguishing the established are or arcs is imposed only upon the main contacts and not at the resistance contacts.

During the closing operation, the construction is such that the main driving frame, carrying the movable main contact or contacts, carries therealong also the movable resistance contact-frame, with the contact overlap distance being such that the main contacts are closed prior to the closing of the serially-related resistance contacts, thereby inserting the closing resistance into the circuit momentarily during the closing operation of the high-voltage circuit-interrupter.

10 Claims, 18 Drawing Figures PATENTEDJAN281975 3,863,041

SHEET OlUF 14 FIG. I

PATENIED JAN 8 I975 sum 02 0F 14 HFGZ PATENTEU I975 SHEET 030i 14 MOE PATENTEU 5 SHEET Ch [1F 14 FIG. 5A

CLOSED POSITION PATENIED JAN 2 8 I975 SHEET CSUF 14 CLOSED POSITION FIG.5B

PATENTED M28 I975 SHEEI as or 14 FULLY OPEN POSITION Pmmnm 3,863,041

SHEET 07 0F 14 FULLY OPEN POSITION I Pmmw ws sum as [1F 14 FULLY OPEN POSlTlON Pmminme ms 3,863,041

SHEET 0911f 14 TO OPERATOR 26 CLOSED POSITION PATENTED JAN 2 81975 SHEEI IOUF 14 CLOSED POSITION SHEET 12UF14 PATENTEDJANZBIBTS PATENTED JAN 2 8 I975 SHEET 1R0? 14 FIG. l3

HIGH-VOLTAGE CIRCUIT-INTERRUPTER HAVING A CLOSING RESISTANCE AND IMPROVED SHUNTING-RESISTANCE CONTACTS THEREFOR CROSS-REFERENCES TO RELATED APPLICATIONS Reference may be made to U.S. Pat. Application filed Dec. 17, 1973, Ser. No. 425,670, by Hayes 0. Dakin, Lawrence A. Brunson and Frank L. Reese and assigned to the assignee of the instant application, which shows an alternate latching arrangement for controlling the insertion of a closing resistance and the control of the resistance contacts during the opening operation, so that the extinguishing action occurs only at the main contact or contacts and not at the resistance contacts during such an opening operation of the breaker.

BACKGROUND OF THE INVENTION In U.S. Pat. No. 3,291,947, issued Dec. 13, 1966 to Roswell C. Van Sickle, and assigned to the assignee of the instant application, there is described the function, purpose and desirable ohmic values of a closing resistance, which is inserted into the circuit only during the closing operation of the breaker, and which is out of the circuit, that is shorted out of the circuit, during the opening operation of the breaker. In this U.S. Pat. No. 3,291,947, there is illustrated a rotating bridging type of separable main contact structure with an auxiliary resistance contact associated with each stationary contact, so arranged that the closing resistance, of a desirable specified ohmic value, is inserted into the controlled circuit at a predetermined time diring the closing operation, and is ultimately shorted out in the fully closed-circuit position of the interrupter.

During the opening operation of the aforesaid circuit-interrupter, as described in the aforesaid Van Sickle U.S. Pat. No. 3,291,947, the arrangement is such that the closing resistance is out of the circuit during the opening operation, and the extinguishing action, or arc interruption, occurs only at the separable rotating main contact structure and not at the closing-resistance contacts, which obviously is desirable.

In the aforesaid Van Sickle US. Pat. No. 3,291,947, there is claimed ranges of ohmic resistance values, which have been found to damp, or to entirely eliminate undesirable voltage surges on the controlled line during the closing operation of the circuit-interrupter. This is desirable inasmuch as the existence of highvoltage surges on the controlled line imposes unnecessary voltage stress on the insulation equipment of the line, and creates the concurrent hazard of flashover across such supporting insulating structures or equipment.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided serially related separable main contacts and separable resistance contacts, with a closing resistance in shunt with the separable resistance contacts. The mechanical operating control for the opening of the main contacts, and the opening of the resistance contacts is such that the main frame, carrying the movable main contact structure, is in abutment with the frame for the movable resistance contacts during the closing operation, and the contact overlap distance, relative to the main contacts and resistance contacts, is such that the main contacts close prior to the subsequent closing of the resistance contacts, so that, in effect, the closing resistance is inserted into the circuit momentarily during the closing operation of the interrupter.

During the opening operation of the interrupter. on the other hand, it is desirable to have the closing resistance out of the circuit, and to impose the extinguishing action, or arc-interruption burden only at the main separable contacts and not at the separable resistance contacts to avoid burning and arc erosion at the resistance contacts. To achieve this end, there is provided a lost-motion between the aforesaid two frames by the inertia of the resistance-frame carrying the movable resistance contact, and a relatively light spring, or other light biasing means, is employed to effect the opening of the resistance-frame for the movable resistance contact. As a result, in the fully open-circuit position of the interrupter, the two equipment frames are again in abutment and in readiness for a subsequent closing operation of the interrupter. However, during the initial portion of the opening operation, the inertia of the resistance-frame for the movable resistance contact insures that the separable resistance contacts will remain closed, thereby shorting the closing resistance out of the circuit during such an opening operation, and also insuring that the arc-extinguishing action occurs only at the main separable contacts adaptable for this purpose, and not at the separable resistance contacts.

Further objects and advantages of the invention will readily become apparent upon reading the following specification taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end elevational view of a three-phase circuit-interrupter of the gas-blast type embodying the principles of the present invention;

FIG. 2 is a side-elevational view of the three-phase gas-blast circuit-interrupter of FIG. 1; FIG. 3 is a top plan view of the three-phase gas-blast circuitinterrupter of FIGS. 1 and 2;

FIG. 4 is a somewhat diagrammatic view of the operating linkage and ground-potential mechanism for actuating the valve-tripping rods for pneumatically actuating the three pole-units of the three-phase gas-blast circuit-interrupter of FIG. 1, the valve-linkage being illustrated in the closed-circuit position of the circuitinterrupter;

FIG. 5A is an enlarged side-elevational view, partially in vertical section, of the upper main arc-extinguishing unit of one-half of a pole-unit of the breaker, the contact structure being illustrated in the closed-circuit position;

FIG. 5B shows the lower portion of the breaker of FIG. 5A, again the contacts being shown closed;

FIG. 6A is a vertical sectional view of the upper main contact structure for the upper main arc-extinguishing unit, the illustration showing the separable main contacts in the fully open-circuit position;

FIG. 6B is a fragmentary enlarged view of the lowermost main contact structure showing the latter in the fully open-circuit position. It will be noted that this extinguishing structure is in series with the upper main contact structure shown in FIG. 6A;

FIG. 6C is an enlarged vertical sectional view showing the separable resistance contacts with these contacts in the fully open-circuit position of the interrupter;

FIG. 7A is an enlarged vertical sectional view taken through the-upper arc-extinguishing unit of the structure illustrated in FIG. 5, again with the contact structure being illustrated in the closed-circuit position;

FIG. 7B is a generally vertical sectional view taken through the second main contact structure of the arcextinguishing unit disposed immediately below the upper arc-extinguishing unit, illustrated in FIG. 7A,

again the contact structure being illustrated in the closed-circuit position;

FIG. 7C is an enlarged vertical sectional view taken through the lower separable resistance contacts, the resistance contacts being illustrated in the closed-circuit position;

FIG. 8 is a diagrammatic view of the circuit illustrating the location and arrangement of the two main arcextinguishing units for each'side of the pole-unit, with an indication of the location of the closing-resistance contacts, and the relationship of the closing resistance relative to the separable resistance contacts, all of the contacts being illustrated in the closed-circuit position of the circuit-interrupter; I

FIG. 9 is a view similar to FIG. 7C, but indicating the intermediate position of the separable resistance contacts during the opening operation, in which the main frame has pulled upwardly away from the lower resistance-frame, connected to the lower movable resistance contact structure, this FIG. 9 illustrating the lost-motion connection between the two frames, wherein the upper main frame has pulled away from the lower resistance-frame;

FIG. 10 is a sectional view taken substantially along the line X-X of FIG. 5A;

FIG. 11 is a sectional view taken substantially along the line XI-XI of FIG. 5A;

FIG. 12 is a top plan view of the closing-resistance assemblage of FIG. 13; and,

FIG. 13 is a generally side elevational view of the closingresistance assemblage.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, and more particularly to FIGS. 1-4 of the drawings, it will be noted that there is illustrated a three-phase high-voltage circuitinterrupter of the gas-blast type 1, such as set forth in US. Pat. No. 3,596,028, many detailed component parts of which are described in said patent, and also in the patents referred to in said U.S. Pat. No. 3,596,028. Various details of the operating structure may be gleaned from a reading of the aforesaid US. Pat. No. and the patents therein referred to. However, for an understanding of the present invention, it is merely neces sary to know that each column structure 3, 4 contains two main arc-extinguishing units 6 and 7 together with a lower resistance unit 9, which has the resistance contacts 11, 12 thereof controlled in such a manner that during the closing operation of the interrupter l, the closing resistance 14 is inserted serially into the circuit to damp any high voltage surges occurring on the line 16 (FIG. 1). However, as will be obvious, in the fully closed-circuit position of the interrupter 1, it is desirable to shunt, or to take the resistance 14 out of the circuit due to heating effects and energy losses, and the function of the separable closing contacts I1, 12 is to achieve this end.

During the opening operation, on the other hand, it is desirable to have the resistance 14, which serves only a closing function, completely out of the circuit 16 during the opening operation. As a result, the closing resistance 14 is shunted out of the circuit 16 during the initial portion of the opening operation, where the task of interrupting the arcs 18, 19 is imposed only on the main contact structures 21, 22, and not at the resistancecontact structure 11, 12. In the particular embodiment under discussion, and as illustrated in FIGS. l-4, there are providedtwo main contact structures 21, 22 and a lower serially related resistance contact structure 11, 12 on each slanting column structure 3, 4, such as illustrated in FIG. 1. Reference may be made to the diagrammatic view of FIG. 8 for an indication of the fact that there are provided six breaks through the entire circuit 16 from L through the two main contact structures 21 and 22 of the left-hand column 3, through the lower resistance contact structure 11, 12 of the lefthand column 3, through a generally U-shaped conductor tube 24 (FIG. 1), and through the right-hand slanting column structure 4, in a similar manner, to the upper line terminal L of the interrupter 1.

With further reference to FIG. 1 of the drawings, it will be observed that there are provided two identical interrupting assemblages 3 and 4 slantingly arranged away from each other, as illustrated in FIG. 1, and each of which contains two serially related main contact assemblages 21, 22, together with a serially related separable resistance contact assemblage 13, which controls the insertion of the closing resistance 14.

Disposed at the upper end of the columnar assemblage 3 of FIG. 5A is an operator, or driving mechanism 26, more fully illustrated in US. Pat. No. 3,590,189, issued June 29, 1971 to Fischer et al., and assigned to the assignee of the instant application. To understand the present invention, however, it is only necessary to know that downward movement of the operator, generally designated by the reference numeral 26 in FIG. 5A, effects closing downward operation of the contact structures 13, 21 and 22. Conversely, upward linear movement of the operator 26, together with the main frame assembly 28, comprising the operation rods 30, 31 of FIG. 6A, will cause opening movement of the main contact structures 21 and 22. It is an important feature of the present invention that there are two frame-assemblies 28, 33 utilized. The upper frame-assembly 28 includes a generally I-I-shaped structure including transverse bridging members 39, 40, together with a pair of downwardly extending interconnecting movable operating rods 30, 31. The lower ends of the operating rods 30, 31 are hollow, as indicated at 42 in FIG. 7C, and make separable abutment connection at 44 with a resilient bumper 46, such as of rubber, affixed to and secured to an upper crossmember 48 attached to the lower frame-assembly 33 associated with the movable resistance contact 11, as illustrated in FIGS. 6C, 7C and 9 of the drawings.

During the downward closing operation of the circuit-interrupter 1, it will be observed that the light spring 50, (FIG. 6C) maintains the two frame-members 28 and 33 in abutment, as at the separable connection 44 in FIG. 6C, so that the downward closing movement of the three contact structures 21, 22 and 13 is simultaneous. The overlap distance of the two main movable contacts 20, 23, relevant to their associated stationary contacts 25, 27, is such that they make contacting closing engagement before the closing engagement of the movable resistance contact 11 with its stationary resistance contact 12. This results in the closing resistance 14 being inserted into the circuit 16 prior to the closing of the resistance contacts 11 and 12 by roughly onehalf cycle time duration. Thus, in the closed-circuit position, all of the contacts are closed, but due to the contact overlap distance at the stationary main contacts 25, 27, the main separable movable contacts 20, 23 make contacting electrical engagement prior to the subsequent closing of the resistance contacts 11, 12 due to the physical dimensions of the contact members utilized.

In the closed-circuit position of the circuitinterrupter l, as illustrated in FIGS. 7A, 7B and 7C, the circuit 16 is closed through the two columnar assemblages 3, 4, and the resistance 14 is out of the circuit, as caused by the closing of the shunting resistor contacts 11 and 12.

The shunting of the closing resistance 14 is, of course, desirable as well appreciated by those skilled in the art, inasmuch as it would lead to heating and energy losses in the closed-circuit position of the interrupter 1. Its use during the closing operation is to avoid the occurrence of high-voltage surges occurring on the line 16 during a closing operation. The theory and functioning of a closing resistance of the proper value is, of course, set forth in the aforesaid Van Sickle U.S. Pat. No. 3,291,947, to which reference has been made and the subject matter of which is incorporated herein by reference.

During the opening operation, it is, of course, desirable for the erosion and burning associated with the extinguishing of the arcs 18, 19 to occur only at the main two contact assemblages 21, 22 in the upper portion of the columnar arc-extinguishing assemblage 3. The arrangement is such that the inertia of the lower resistance frame-assembly 33 is such that it hangs behind, or there is a lost-motion connection 32 between the two frame-assemblages 28 and 33 due to the inertia of the lower resistance frame-assemblage 33 and the relatively light biasing spring 50 of FIG. 7C. The net result is that the operator 26 has sufficient driving force to quickly and rapidly accelerate the upper frameassembly 28, together with its associated two moving main contacts 20, 23, to break the circuit 16 at these points, whereas the resistance contacts 11, 12 are yet closed, thereby shorting out the closing resistance 14, and thus imposing all arcing 18, 19 upon the upper two serially related main arc-extinguishing structures 6, 7.

By the time that the relatively light spring 50 of FIG. 7C raises the lower resistance frame assembly 33 to effect contact break at the resistance contacts 11 and 12, at this time arcing 18, 19 inthe upper two serially related units 6, 7 has ceased, arcing is out and thus there is no arc erosion or burning at the lower separable resistance contacts 11 and 12.

The closing resistance assemblage 14 is more clearly set forth in FIGS. 12 and 13, where it will be observed that the carbon arcuate segments 54 are in compression, as caused by the compression springs 56, and connections 58 between the carbon resistance segments cause the resistance assemblage 14 to be of the right ohmic value, as set forth in the aforesaid Van Sickle U.S. Pat..No. 3,291,947.

With reference to the lower end of the columnar assemblage 3 it will be observed that there is a lower nose-shaped guide portion 60, which is guided into the upper open end of a generally U-shaped conductor tube, as indicated by the reference numeral 71 in FIG. 5B of the aforesaid Kane et al., Pat. No. 3,596,028.

Although the above description has been centered around one columnar assemblage 3, it will be noted that the same description is appropriate for the other slantingly arranged columnar arc-extinguishing assemblage 4, which has a generally identical construction and function. As a result, there are four main separable contact structures in each pole-unit A, B, or C, as shown in FIG. 8. The function of these four main contact structures is to interrupt the electrical current flow through the pole-unit A during the opening operation, and the four separable main contact structures distribute the arcing 18, 19, and voltage division among the four series breaks is controlled by shunting capacitor branches paralleling the interrupting assemblages. These are designated by the reference numerals 62 and 63 of FIGS. 7A and 513;

It is to be further noted that in each pole-unit A, B, or C there is provided the two closing resistances 14 together with their associated separable resistance contact assemblages 13, which function, during the opening operation, to keep the resistances 14 out of the circuit 16 during the interruption process. During the closing operation of the interrupter 1, on the other hand, the main contact structures 21, 22 are closed, whereas the separable resistance contacts 11, 12 are still open, so that the two resistances 14 are serially inserted into the circuit 16 during the closing operation to prevent high-voltage surges occurring on the line 16.

As set forth in FIG. 4, a main operating mechanism 64 at ground potential, which is described in U.S. Pat. No. 3,642,329, which issued November 30, 1971 to Fischer et a1, effects rightward movement of an operating lever 66, which, through a connecting rod 68, effects counterclockwise rotation of two bell-crank levers 70, 71, each of which has an upstanding movable valve-rod 73 (FIG. 10) pivotally connected thereto at 75. The two bell-crank levers 70, 71 are pivotally mounted on stationary pivots 77, 78. The central bellcrank lever 70 is pivotally connected, by a connecting rod 80, to the left-hand bell-crank lever 82, which moves in a clockwise direction about a stationary pivot 84. Pivotally connected at 86 to the left-hand bellcrank lever 82 is the upstanding valve-rod 73 associated with the pole unit A.

An accelerating spring 90, shown in FIG. 4, bears 1 against a cap portion 92 affixed to the left-hand extremity of a guide-rod 94, the right-hand end of the lat ter being pivotally connected to the left-hand bellcrank lever 82. Accordingly, clockwise pivotal rotation of the driving lever 66 effects upward movement of all three valve-rods 73, which serve to pneumatically cause pressure to occur on the bottom side of an operating piston (not shown) constituting a part of the operator 26 illustrated in FIG. 5A of the drawings.

The operator 26 is set forth and described in U.S. Pat. No. 3,590,189, and during the closing operation, as described hereinbefore, causes downward movement of the I-I-shaped frame 28 comprising the two operating rods 30, 31 movable within stationary guide sleeves, or tubes 96, 97, and serving to simultaneously cause the downward closing movement of the two main movable contacts 20, 23.

As set forth in U.S. Pat. No. 3,596,028, a latching arrangement 100 (FIG. 7A) is associated with each main movable contact or 23, as disclosed more clearly in FIG. 6B of the drawings. It will be observed that there are provided a pair of pivotally mounted latches 102 biased radially inwardly by a pair of compression springs 104, only one latch assembly 102 being viewed in FIG. 6B of the drawings. The construction is such that during the closed position, as viewed in FIG. 7A, the latches seat upon shoulder portions 106 associated with the secondary blast-valves 107, which, when open, permits gas flow to occur out ports 108 associated with the rear side of the upper movable main contact 20, as viewed in FIG. 6A. This gas-flow action is described in more detailin U.S. Pat. No. 3,596,028 to which reference may be made, and the subject matter of which is incorporated herein be reference.

Following a predetermined opening motion of the movable contact structure 20 or 23, a portion 103 of the movable contact structure bears on a cam portion 101 of the latches 102, forcing the latches 102 outwardly to thereby release the blast-valves 107, which move upwardly to the closed position, thereby halting any gas flow out of the interrupting chamber 88 (FIG. 6A) in the open position of the main contacts, as illustrated in FIGS. 6A and 6B of the drawings. It will be noted that there exists at all times high-pressure gas within the region externally of the main contact structure, as designated by the reference numeral 99 in FIG. 6B of the drawings. This high-pressure gas is available immediately upon separation of the contacts to effect extinction of the arcs l8, 19, which are indicated in the drawings, although the contact structure is illustrated in the fully open position in FIGS. 6A and 6B of the drawings.

FIGS. 6B and 7B show more clearly the mechanical interconnection of the movable main contact 23 of the lowermost main arc-extinguishing structure 7. It will be observed that a cross-member is mechanically interconnected between the two operating rods 30, 31, and

' serves somewhat the same function as the upper traverse member 39 of FIGS. 6A and 7A. As mentioned hereinbefore, the two main operating rods 30, 31 have lower hollow extensions 42 which encompass projections 35 affixed to the lower traverse frame-member 48 of the resistance assemblage 33, as indicated more clearly in FIGS. 7C and 9 of the drawings. The lostmotion between the lower hollow tubular extensions 30a, 31a of the two main operating rods 30, 31 and the resilient rubber bumpers 46, affixed to the resistance traverse member, is designated by the reference numeral 32 in FIG. 9, and the distance at this particular point of time is designated by the distance length D in FIG. 9 of the drawings. Consequently, FIG. 9 illustrates a point in time during the opening operation of the interrupter 1 in which the main movable resistance contact 11 has lagged behind to short out the closing resistor 14, while the upper two breaks 21, 22 are causing the extinction of the arcs 18, 19 within the interrupter l.

Also associated with each columnar assemblage 3, 4 is an outer cylindrical insulating casing member 10, which holds the high-pressure gas 8 within the regions 99 externally of the two main contact structures 21, 22. Also, it will be noted that externally of the insulating casing member 10 is disposed an outer porcelain casing 15 utilized for its weatherproof characteristics. Suitable means, not shown particularly, and not pertinent to the present invention, are provided for applyingcompressive force on the outer porcelain casing member 15 and corresponding tensile stress upon the inner insulating tubular casing 10. The upper line connection L. is secured to a terminal structure 34 more clearly shown in FIG. 5A, which electrically connects the circuit 16 to the upper main movable contact 20. As set forth in the aforesaid Kane et al., U.S. Pat. No. 3,596,028. the circuit 16 extends through both columnar assemblages 3. 4 and terminates at the upper end 34 of the other assemblage 4 of FIG. 1.

As observed hereinbefore, the inertia of the lower frame 33 comprising the traverse member 48, the movable resistance contact rod 87 and lower cup-shaped resistance contact member 11 is such that there occurs a lost-motion connection 32 (FIG. 9) with the upper rapidly moving main frame-structure 28 connecting the two main movable contacts 20, 23 mechanically together, and moving upwardly at very high speed during the opening operation of the breaker 1. Also, the compression spring 50 of FIG. 9 is relatively light and thereby incapable of maintaining abutment at the connection 44, thus permitting the upper frame 28 to pull away from the lower frame 33 during the initial portion of the opening operation of the breaker. At a subsequent point of time, when the upper frame 28 has moved to its upper fully open position, the relatively light spring 50 is sufficiently adequate to force the lower resistance-frame 33 upwardly to the abutment position, as illustrated in FIG. 6C of the drawings. At this point in time, the circuit-interrupter 1 is fully open, the abutment connection made at 44 and the breaker l capable of being closed in the manner heretofore described.

From the foregoing description it will be apparent that a novel arrangement has been provided, in connection with a closing resistance 14 and associated separable resistance contact structure 13, controlling the insertion of the closing resistance 14 into the circuit 16 only during the closing operation of the breaker 1. During the opening operation of the breaker, the closing resistance 14 is deliberately shorted out of the circuit 16, so that the full burden of arc-extinction 18, 19 is imposed only on the upper two main separable contact structures 21, 22, and no arcing occurs at the separable resistance contacts 11, 12. The inertia of the resistance frame 33 and the relatively light spring 50 are thus utilized to afford the desirable delaying, or lost-motion effect 32 for the lower resistance frame-member 33.

Suitable mechanical support tubes 59, 61 are provided to fixedly maintain the stationary contact structures 25, 27 in the desired stationary location, and to provide mechanical integrity of the arc-extinguishing assemblage 3 as a whole.

With reference to FIG. 2 it will be observed that a low-pressure tank 29 is provided together with compressor equipment, as set forth in U.S. Pat. No. 3,596,028. The high-pressure reservoir for providing high-pressure in the regions 99 around the separable main contact structures 21, 22 are provided within the U-shaped connecting tube 71 of FIG. 5B of U.S. Pat. No. 3,596,028, the subject matter of which is incorporated herein by reference.

The manner of arc-extinction and the operation of the various parts is also more clearly set forth in the aforesaid US. Pat. No. 3,596,028.

This resistor contact is for use in a high voltage power circuit breaker rated at 362 kV. The breaker is capable of 40 kA interrupting ability and carrying 3,000 Amps continuously. The pre-insertion resistors are available from 175 ohms to 300 ohms each. There are two of these per phase. They are electrically and thermally capable of closing into a full fault four times each hour. The contact shorts out the resistor from 6 to 9 milliseconds after it has been inserted into the circuit. The use of a closing resistor optimally sized for each system reduces the over-voltages caused by closing the circuit breaker into a transmission line with a trapped charge, and subsequently reduces the electrical stress imposed on the entire power system's equipment. This stress is reduced to a miximum of 2.0 times the normal line to ground voltage whereas this maximum is 3.0 times the normal line to ground voltage when no closing resistor is used.

Although there has been described a specific structure, it is to be clearly understood that the same was merely for the purpose of illustration, and that changes and modifications may readily be made therein by those skilled in the art without departing from the spirit and scope of the invention.

We claim:

1. A high-voltage circuit-interrupter of the type for eliminating high-voltage surges on the controlled line comprising, in combination:

a. means defining a separable pair of main contacts including a movable main contact;

b. an operator for effecting the opening and closing motions of said separable pair of main contacts;

c. means defining a separable pair of resistance contacts including a movable resistance contact disposed in electrical series relationship with said separable pair of main contacts so that in the closed-circuit position of the circuit-interrupter the line current passes serially through the two pairs of separable contacts;

d. means defining a closing resistance connected electrically in shunt with said separable pair of resistance contacts so that when said separable pair of resistance contacts are closed the closing resistance is shorted out of the controlled circuit;

e. said operator including a first movable member responsive to the movement of said movable main contact;

f. a second movable member responsive to the movement of said movable resistance contact;

g. means biasing said second member and said movable resistance contact to the open-circuit position;

h. said first and second movable members being in an abutment condition in the fully opemcircuit position of the circuit-interrupter;

i. said first movable member forcing said second movable 'member and consequently the movable resistance'contact into the closed-circuit position during the closing operation of the circuitinterrupter against the tension exerted by said biasing means;

j. said operator providing sufficient velocity of said first movable member during the' opening operation of the circuit-interrupter and the inertia of said second movable member being so great that said second movable member lags behind the first movable member during the opening operation of the circuit-interrupter;

k. and means effecting the closing of the separable pair of main contacts during the closing operation of the circuit-interrupter prior in point of time to the closing of the separable pair of resistance contacts so that the closing resistance is connected serially into the controlled circuit during the closing operation and subsequently shorted out by the delayed closing of the separable resistance contacts, whereby high-voltage surges on the controlled line tend to be eliminated.

2. The combination of claim 1, wherein the contact overlap of the separable pair of main contacts is greater than the contact overlap of the separable pair of resistance contacts.

3. The combination of claim 1, wherein a plurality of pairs of main contacts are provided in series for the high-voltage applications.

4. The combination of claim 1, wherein gas-blast means are provided to extinguish arcing at the separable main contacts.

5. The combination according to claim 4, wherein the movable main contact is hollow and the extinguishing gas flow passes through said hollow movable main contact during the interruption process.

6. The combination according to claim 3, wherein the first member is a generally H-shaped framemember which actuates all of the movable main contacts simultaneously.

7. The combination according to claim 1, wherein the second movable member comprises a traverse having its ends abutting the two operating rods comprising a portion of the first member.

8. The combination according to claim 1, wherein the extinguishing gas comprises sulfur-hexafiuoride (SP gas.

9. The combination according to claim 1, wherein the first member comprises two operating rods.

10. The combination according to claim 9, wherein the lower ends of the two operating rods are hollow and accommodate protrusions constituting a part of the second movable member. 

1. A high-voltage circuit-interrupter of the type for eliminating high-voltage surges on the controlled line comprising, in combination: a. means defining a separable pair of main contacts including a movable main contact; b. an operator for effecting the opening and closing motions of said separable pair of main contacts; c. means defining a separable pair of resistance contacts including a movable resistance contact disposed in electrical series relationship with said separable pair of main contacts so that in the closed-circuit position of the circuitinterrupter the line current passes serially through the two pairs of separable contacts; d. means defining a closing resistance connected electrically in shunt with said separable pair of resistance contacts so that when said separable pair of resistance contacts are closed the closing resistance is shorted out of the controlled circuit; e. said operator including a first movable member responsive to the movement of said movable main contact; f. a second movable member responsive to the movement of said movable resistance contact; g. means biasing said second member and said movable resistance cOntact to the open-circuit position; h. said first and second movable members being in an abutment condition in the fully open-circuit position of the circuitinterrupter; i. said first movable member forcing said second movable member and consequently the movable resistance contact into the closed-circuit position during the closing operation of the circuit-interrupter against the tension exerted by said biasing means; j. said operator providing sufficient velocity of said first movable member during the opening operation of the circuitinterrupter and the inertia of said second movable member being so great that said second movable member lags behind the first movable member during the opening operation of the circuitinterrupter; k. and means effecting the closing of the separable pair of main contacts during the closing operation of the circuitinterrupter prior in point of time to the closing of the separable pair of resistance contacts so that the closing resistance is connected serially into the controlled circuit during the closing operation and subsequently shorted out by the delayed closing of the separable resistance contacts, whereby high-voltage surges on the controlled line tend to be eliminated.
 2. The combination of claim 1, wherein the contact overlap of the separable pair of main contacts is greater than the contact overlap of the separable pair of resistance contacts.
 3. The combination of claim 1, wherein a plurality of pairs of main contacts are provided in series for the high-voltage applications.
 4. The combination of claim 1, wherein gas-blast means are provided to extinguish arcing at the separable main contacts.
 5. The combination according to claim 4, wherein the movable main contact is hollow and the extinguishing gas flow passes through said hollow movable main contact during the interruption process.
 6. The combination according to claim 3, wherein the first member is a generally H-shaped frame-member which actuates all of the movable main contacts simultaneously.
 7. The combination according to claim 1, wherein the second movable member comprises a traverse having its ends abutting the two operating rods comprising a portion of the first member.
 8. The combination according to claim 1, wherein the extinguishing gas comprises sulfur-hexafluoride (SF6) gas.
 9. The combination according to claim 1, wherein the first member comprises two operating rods.
 10. The combination according to claim 9, wherein the lower ends of the two operating rods are hollow and accommodate protrusions constituting a part of the second movable member. 